Decided to restore this once we’d sorted the baseplate. About 1/2 way through, main rail caps upgraded, one bank of 12v caps removed. Once these are replaced with uprated parts the preamp gets the works.
Preamp mostly upgraded, just waiting on some Holco resistors. Orange * parts uprated already, black X parts still to be done.The preamp is the weakest link of the amp and upgrading it should yield significant improvements.